Waterford 3 – NRC Public MeetingFebruary 4, 2014

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NFPA 805 LAR Supplement

◦ Introduction◦ Changes to Supporting Analyses◦ Resulting Impact to:� Risk (CDF, LERF)� Modifications and Implementation Items� Recovery Actions ◦ LAR Attachment Change Summary◦ Comparison of Risk Areas to Original LAR◦ Impact on RAIs◦ Questions/General Discussion

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Agenda

Updated Internal Events PRA and Fire PRA • Resolved Request for Additional Information (RAIs)• Updated Fire PRA to use accepted methods.• Corrected legacy issues• Update to the Nuclear Safety Capability Assessment (NSCA)

impacted Variance from Deterministic Requirements (VFDRs) and Recovery Actions

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Introduction

◦ Addressed RAI’s• Resolved Peer Review F&O’s• CCW Makeup◦ Ultimate Heat Sink Modeling (Fan Requirements)◦ HVAC Requirements by Fire Area/Room◦ LERF

• Containment Isolation Size Threshold (> 2 Inches)• Containment Atmosphere Release System (CARS) Modeling

Update o Routine 5 year Update (Plant Changes/Data Update)

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Changes to Supporting AnalysisInternal Events PRA

◦ Majority of Changes Addressing RAI’s• Updated to use accepted methods• Control Room Abandonment Analysis (CCDP)• Fire Modeling Changes• Refined Transient and Fixed Source Scenarios• Refined MCA including Sensitive Electronics◦ Fire Scenario Analysis ◦ Transient Combustible Analysis

• Heat Release Rates (HRRs) increased• Secondary Combustibles (RAB 27 impact)

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Changes to Supporting AnalysisFire PRA

◦ Transient Combustible Fire Heat Release Rates • 69 kW to 317 kW◦ Severity Factor for Severe Pump Oil Fires

• 2/98 to 10/90 Large oil pump fire/Small oil pump fire split fraction

◦ Adjustment Factors Removed• Transient Combustible Fire Ignition Frequency• Hot Work Ignition Frequency • Electric Cabinet Fire Ignition Frequency

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Changes to Supporting AnalysisAddressed RAIs Related to PRA Methods

◦ EDG Severity Fire Factor Removed◦ Use of assumed CCDP (Probability of mitigation failure) to

calculated value• Control Room Abandonment • TGB Structural Failure

o Sensitive Electronics – Temperature threshold for damage

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Changes to Supporting AnalysisRAIs Addressed in Supplement

◦ Separated NSCA and SSA Calculations◦ VFDR list re-validated

• Removed Cold Shutdown (CSD) VFDRs• Removed unnecessary VFDRs for Recovery Actions, Heymc and

multiple Success Paths◦ VFDRs identified in 3 additional Fire Areas: TGB, EDG A,

and CCW HX A◦ Removed credit for Partial Height Walls:

• Relay Room (RAB7)• Switchgear Room (RAB8)

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Changes to Supporting AnalysisNuclear Safety Capability Assessment (NSCA)

◦ 3 New FREs prepared for TGB, EDG A, and CCW HX A Fire Areas◦ Relay Room (RAB 7) Analyzed as one Fire Area◦ Switchgear Room (RAB 8) Analyzed as one Fire Area◦ Single Recovery Action to Manually Trip RCP Motor

Breakers in 4 Fire Areas (RAB 1, RAB 7, RAB 8, TGB)◦ N2 Accumulator mission time increased to 24 hours

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Results due to Analysis ChangesFire Risk Evaluations (FREs)

o 22 MOVs Require Modification to eliminate IN 92-18 Concerns

o Fire Area RAB 6 requires ERFBS to support Risk Assumptions (4 Fire Areas in Original LAR)

o Radiant Barrier not required in RAB 2 to protect the Essential Chillers

o HEAF Barrier not required in Fire Area RAB 8o Secondary Combustible removal in Fire Area RAB 27

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Resulting ImpactsOriginal LAR Supplement

RiskCDF 3.4 E-5 1.62 E-5

∆ CDF 8.4 E-6 2.31 E-6LERF 7.3E-7 2.89 E-6

∆ LERF 1.1E-7 1.29 E -7Number of Mods

MOVs 15 22 ERFBS (wrap) 4 1HEAF Barrier 1 0

Radiant Barrier 1 0Code Compliance 7 7

Recovery Actions 30 4 Same RA in 4 Areas

Attachment A (B-1 Table)• Section 3.3.8 revised to state WF3 does not have Bulk Storage of

Flammable Liquids located in Structures containing SSCs important to nuclear safety

• Section 3.11.5 revised to state ERFBS required in Fire Area RAB 6 only

Attachment B (B-2 Table) • NEI 00-01 Rev 1 to Rev 2 Gap Analysis updates

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Attachment Change Summary

Attachment C–Table C-1 (B-3 Table)• Regenerated to reflect 31 new/revised FREs and revised format• Revised Licensing Actions (Attachments K and T)

Attachment C – Table C-2 (Formerly Table 4-3) • Regenerated to reflect 31 new/revised FREs and Revised format• Revised Licensing Actions (Attachments K and T)

Attachment G – (Recovery Actions)• Recovery Actions changed due to revised FREs� Single Action (Manually Trip RCP Motor Breakers in TGB Switchgear)� 4 Fire Areas (RAB 1, RAB 7, RAB 8, TGB)

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Attachment Change Summary

Attachment H (FAQs)• Updated to reflect revised FPRA methods

• Added� 06-0016 “Ignition source counting guidance for Electrical Cabinets”� 06-0017 “Ignition source counting guidance for High Energy Arcing Faults

(HEAF)”� 06-0018 “Ignition source counting guidance for Main Control Board (MCB)”� 10-0059 (updated to Revision 5) “Monitoring Plan”

• Removed� 08-0042 “Fire propagation from electrical cabinets” (Did not screen any

cabinets due to being “sealed” construction)� 08-0044 “Large spill oil fire size” (not used)

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Attachment Change Summary

Attachment J (Fire Modeling V&V)• Regenerated due to changes in Fire Modeling

Attachment K (Licensing Actions)• LAR Supplement transitions 5 Deviations (12, 16, 36, 42 & 43)

• Original LAR transitioned 23 NRC-approved Deviations• 13 Deviations not required per New GL 86-10 evaluations• 5 Deviations not required under NFPA 805 Separation requirements

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Attachment Change Summary

Attachment S (Plant Modifications and Implementation Items)◦ Table S-1 Revised/New

� S1-1 revised list of MOVs due to IN 92-18 Evaluation Update� S1-5 Removed ERFBS (fire wrap) requirements for Fire Areas RAB 2, RAB

5, RAB 17� S1-8 Updated text in “Risk Informed Characterization” column� S1-14 (New) Action to remove combustibles from Fire Area RAB 27� S1-15 (New) Added MOVs to modify to eliminate IN 92-18 failure

mechanism on valves that their failure is undesirable, however are not credited in the FREs.

◦ Table S-1 Deletions� S1-2 no MOVs needed to modify for NPO. � S1-3 HEAF Barrier in RAB 8(c) not required� S1-4 Radiant Barrier in RAB 2 not required� S1-6 Recovery Actions that required additional lighting (local operation of

HVAC components) not required

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Attachment Change Summary

Attachment S (Plant Modifications and Implementation Items)o Table S-2 Items� S2-8 Revised to add procedure EN-DC-161 “Control of

Combustibles” to support DID recommendations� S2-21 (New) Revise surveillance procedure to preserve fire scenario-

specific mission time assumptions in Fire PRA for selected Nitrogen Accumulators

� S2-22 (New) Verify the validity of the analysis results post-mod and procedure updates

� S2-9 Deleted, floor markings are not required

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Attachment Change Summary

Attachment T (NRC Clarifications)� 2 previous Clarifications deleted due to completion of new GL

86-10 Evaluations� Control Room Barrier� EDG removable wall panels

Attachment U (Internal Events PRA Quality)• Regenerated due to revised models and Focused Peer Reviews

• 51 Total F&Os• All 37 Impacting FPRA Closed• 14 Open F&Os with no impact on FPRA

• 8 deal with Flooding Analysis• 6 related to internal PRA documentation

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Attachment Change Summary

Attachment V (Fire PRA Quality)� Updated to include F&Os and corresponding dispositions from

new Focused Scope Peer Review of the Fire PRA � Removed Section V.2 which provided Alternate Methods

Sensitivity

Attachment W (Fire PRA Insights)• Regenerated due to revised Fire PRA and FREs

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Attachment Change Summary

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Resulting Fire Area Ranking

Supp

lem

ent

rank

CDF

LAR

ran

k

CDF Notes

RAB 1 1 6.90E-06 3 3.17E-06 Doubled due to detailed MCR abandonment analysis

RAB 7 2 4.33E-06 2 3.67E-06

Similar number - increase due to multi-compartment and sensitive electronic issues, but reduced due to re-mapping corrections

RAB 8 3 2.55E-06 1 1.63E-05Updated number smaller by factor of 10 primarily due to component mapping (limited dual bus failures)

TGB 4 1.01E-06 20 3.12E-08TGB much higher now due to removal of oil fire split fraction and use of plant specific suppression reliability

RAB 15 5 3.84E-07 7 5.63E-07 Higher due to removal of split fraction method for EDG fire

RAB 16 6 3.01E-07 14 1.43E-07 Higher due to removal of split fraction method for EDG fire

RAB 31 7 1.92E-07 18 3.55E-08Increase due to update transient methodology (higher HRR with larger ZOI = more targets).

YARD 8 1.37E-07 5 7.88E-07Yard was redefined to include Fire Pump House and Condensate Polisher Bldg

RAB 2 36 1.20E-09 4 3.00E-06Reduced due to removal of HVAC requirements from PRA model for many areas.

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Resulting Scenario Ranking (Top 9)LAR Scenario CDF

% Total CDF Supplement Scenario CDF

% Total CDF

31AB SWGR Fire with HEAF 1.12 E-5 32.8 MCR Transient Fire w/ HVAC 2.43 E-6 15.0

Aux Panel 4 Fire 2.82 E-6 8.3 3B SWGR Fire with HEAF 7.17 E-7 4.4

1B SWGR Fire (7kV) 1.33 E-6 3.9 MCR Transient Fire w/ No HVAC 7.16 E-7 4.4

CP-10 Fire 1.03 E-6 3.0Relay Room Fixed Source Fire MCA 6.64 E-7 4.1

3B SWGR Fire with HEAF 7.46 E-7 2.2

Relay Room Transient Fire in RAB 7A 5.24 E-7 3.2

Oil Fire A & B Chillers 6.88 E-7 2.0Relay Room Fixed Source Fire MCA 4.42 E-7 2.7

Chilled Water Pump A Oil Fire (Moderate) 6.61 E-7 1.9

Relay Room Fixed Source Fire MCA 4.42 E-7 2.7

Chilled Water Pump B Oil Fire (Severe) 6.61 E-7 1.9

MCR Electrical Cabinet Fire with HVAC and abandonment 4.42 E-7 2.7

ESFAS 3A Panel Fire 5.65 E-7 1.7MCR Electrical Cabinet Fire with No HVAC and abandonment 3.03 E-7 1.9

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Resulting ImpactsOriginal LAR Supplement

RiskCDF 3.4 E-5 1.62 E-5

∆ CDF 8.4 E-6 2.31 E-6LERF 7.3E-7 2.89 E-6

∆ LERF 1.1E-7 1.29 E -7Number of Mods

MOVs 15 22ERFBS (wrap) 4 1HEAF Barrier 1 0

Radiant Barrier 1 0Code Compliance 7 7

Recovery Actions 30 4 Same RA in 4 Areas

◦ Information contained in many RAI responses is superseded by the Supplement and supporting documentation/analysis◦ Some RAI responses provided description of methodology, results

of preliminary analysis or sensitivity studies, with indication of pending future analysis.� In most cases, the descriptions remain valid, however, the numerical

values in the LAR Supplement supersede those in the RAI.� In some cases, the reanalysis replaces the RAI response information in

total.◦ Some RAIs are no longer applicable as the methods in question

have been replaced with methods that are believed to be acceptable.

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Resulting ImpactsRAIs

◦ RAI Responses Superseded by LAR Supplement 1

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Resulting ImpactsRAIs

PRA-01 PRA-20 PRA-33 PRA-45 PRA-56

PRA-07 PRA-21 PRA-34 PRA-47 PRA-57

PRA-12 PRA-23 PRA-35 PRA-50 PRA-58(b)

PRA-13 PRA-28 PRA-38 PRA-51 PRA-59

PRA-16 PRA-29 PRA-42 PRA-53 FPE-05

PRA-17 PRA-32 PRA-44 PRA-54(d) SS-14

PRA-18

1 Preliminary Review

◦ PRA-06 & PRA-40� The methodology discussion in the below RAI responses remain valid, however,

the numerical results from the Supplement should be used in lieu of data from the RAI responses due to new or revised analysis.

◦ PRA-11, PRA-43, PRA-52, SS-02, SS-02.01 a(iii), & SS-06� Revisions to Table S-1 supersedes information in the RAIs.

◦ SS-07, SS-08, & SS-13� Attachment G revisions supersedes information in the RAIs.

◦ PRA-05� Nitrogen accumulator availability duration is 24 hrs

◦ SS-01� NSCA calculation is EC-F13-001, not revision to ECF00-026

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Resulting ImpactsRAIs1

1 Preliminary Review

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Responses to Draft PRA RAIs

RAI # Subject Disposition Basis Refernece

PRA RAI 01.01 Explain how “plausible secondary ignition sources” are defined

Explain: Actual analysis performed

PRA-W3-05-006TPRA-W3-05-006F

PRA RAI 04.01FRE description should clarify how ignition frequency and CCDP are considered together with other aspects of the fire scenario, such as propagation, detection, and suppression.

This process is only briefly covered in the FRE(s) but is in very good detail in the DID report (WF3-FP-13-0004). WF3-FP-13-0004

PRA RAI 10.01 Did FRE results include UAMs as basis for evaluation risk No UAMs, see FM-07 response N/A no UAMs

PRA RAI 16.01 Impact to sensitive electronics in “non-adjacent cabinets”

Analysis accounts for Sensitive electronics, see FM-07 response

PRA-W3-05-006TPRA-W3-05-006F

PRA RAI 25.01

15 minutes for the manual non-suppression probability is “listed time to damage for secondary cable targets of 19 minutes from NUREG/CR-6850"

Cite references for 15 min assumption and sensitive electronics sensitivity study

PRA-W3-05-006TPRA-W3-05-006F

PRA RAI 29.01 (a)PAU ceiling heights of 7 or 12 ft, or the assumed cabinet height of 7 ft, describe how the generic methodology is applied

Explain: Analysis used actual ceiling heights

PRA-W3-05-005 Rev 1

PRA RAI 29.01 (b)Reference is made to two groupings for HRRs, 69 kW and 702 kW. It is unclear where these groupings arise

New methodology conforms to 6850, RAI is no longer applicable

PRA-W3-05-005 Rev 1

PRA RAI 29.01 (c)With regard to the 69 kW HRR grouping discussed in (b), Clarify HGL screening

Explain: 69 kw not used. See FM-07 for HGL discussion

PRA-W3-05-005 Rev 1

PRA RAI 43.01 Clarify which S table items are in PRA model Explain S-1 & S-2 mods. Attachment S

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Responses to Draft PRA RAIs (cont.) RAI # Subject Disposition Basis Refernece

PRA RAI 44.01 (a) PRA data counting method Explain with requested justification Attachment U

PRA RAI 44.01 (b)HEP value based on timing change

The action associated with this RAI (operation of SI-120/121) is no longer credited (CSD) PRA-W3-05-003

PRA RAI 44.01 (c)

PRA RAI 44e and stated that the assumed HEP value for EHFMANTNR has no impact on the FPRA results since the event does not appear in a single cutset

EHFMANTNR in cutset with CDF ~1E-13 in IEPRA. Not in Fire PRA cutset due to truncation PSA-WF3-01-HR

PRA RAI 44.01 (d) WCT success criteria Explain: modeled now PRA-WF3-01-SC

PRA RAI 44.01 (e)The explanation of modeling of the battery in RAI PRA 44h, but did not provide sufficient information Explain: Add detail PSA-WF3-01-SYS

PRA RAI 44.01 (f) Loss of inventory over time considered with flow diversions in Fire PRA?

Explain: 1/3 acceptable flow diversion may impact inventory over time. This consequence in FPRA? PRA-W3-05-040

PRA RAI 53.01 Modeling of SOVs in Fire PRA including SOV's that are part of AOV's

SOV hot shorts included with actuator failure as appropriate (EFW valves, for example) PSA-W3-03-01

PRA RAI 58.01 (a)Clarify "the non-compliant case includes basic events that no credit can be given to when compliant with NFPA 805" Explain: eliminate use of confusing verbiage

PSA-WF3-03-01RSC 13-19

PRA RAI 58.01 (b), (c), (d)

Explain "True" as used in Franx and FPRA Fault trees

The term/verbiage "True" is not longer in the supporting documentation

No longer applicable

PRA RAI 58.01 (e)

VFDRs with "Open" Status

Open’ status in the previous submitted LAR meant that the associated VFDR had a proposed modification associated with it. The updated LAR B-3 does not use the term ‘open’ and has more specific status classifications.

No longer applicable

PRA RAI 60HEP is set to a value of TRUE then the joint human error probability (JHEP) is set to 0. Explain: model should already be fixed PRA-W3-05-043

PRA RAI 61 (a)How failure to isolate component cooling water (CCW) is modeled in FPRA Explain: how are CCW cross connects handled in model PRA-W3-05-040

PRA RAI 61 (b)

How CCW makeup modeled in FPRA. CCW makeup system is not included in the FPRA according to Table B-3 of the LAR

PRA-W3-05-040 was done and the result was to add the CCWMU support to the model. Basically any size flow diversion in CCW may require makup since it is closed loop with fixed inventory. The makup function is not explictly modeled. PRA-W3-05-040

o LAR Supplement• Addresses RAIs • Provides results using methods described in

NUREG/CR-6850 � Overall Risk Results are comparable to original LAR� Minimal Changes to list of Modifications and

Implementation Itemso Waterford 3 will support any additional working level

meeting(s) on technical details necessary for RAI closure.

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Conclusions

Questions?